Marking is understood the punching of particular information, such as for example a date, upon workpieces. It then is a question of date marking.
Known marking devices being currently used are formed of a metal case, generally in two parts, which is fixed to the barrel of the apparatus and which contains a freely moving inertia block, very often urged towards the punches by means of a spring and which, under the action of the piston of the apparatus, in its turn drives the punches, these latter sometimes being held within passages formed within the case, such as, for example taught by means of the documents ER-A-2 389 425 and 2 456 570 for providing marking indicia. The punches may moreover be replaced by means of rotary wheels for a rapid change of characters.
These devices are relatively expensive and exhibit an excessive amount of weight.